Electronic data storage devices allow the storage and retrieval of data accessed under the control of electrical signaling. Many different recording mediums exist for storing the data, each having different characteristics and parameters. Memories used in data storage devices can be classified into categories including volatile memories and nonvolatile memories. Nonvolatile memories, e.g., those using magnetic recording mediums or floating-gate transistors, maintain stored data in the absence of electrical power. Volatile memory, such as Dynamic-Random-Access-Memory (DRAM) or Static-Random-Access-Memory (SRAM), loses stored data when electrical power is removed.
Magnetic-based memory devices store data by magnetizing a magnetic recording medium in a particular orientation. Data is read by passing a sensor over the magnetized areas to detect the orientation of the stored magnetic fields. A common format for magnetic recording mediums uses rotating magnetic platters and read-write heads positioned to read or write to the platters as they rotate. Magnetic recording mediums have the advantage of being non-volatile due to the use of a magnetized medium, which does not require electrical power to maintain stored-data integrity.
Solid-state memory refers to memory that uses semiconductor technology as the storage medium. One type of solid-state memory is nonvolatile flash memory. Nonvolatile flash memory operates by storing charge on a floating gate of a memory cell. In particular, nonvolatile flash stores data by charging a floating gate that maintains the stored charge in the absence of electrical power. Flash memory also has the added benefit of not being as susceptible to mechanical perturbations because it does not require movable parts to access (read/write to) the storage medium.
A particular field of use for both solid-state memory and magnetic-based memory relates to storage devices accessible by electronic systems, and more particularly, computer systems. For example, a conventional hard disc drive (HDD) includes a rotating magnetic media that is accessed under the control of electrical signals provided by an electronic control circuit. Another type of data storage device is a solid-state device (SSD) that uses solid-state memory accessed under the control of electrical signals. When viewed from a programming or memory hierarchical perspective, HDDs and SSDs can look similar or even identical. From a practical standpoint, however, these drives often exhibit a number of important differences including, but not limited to, access speeds, power consumption, reliability and susceptibility to data loss due to mechanical vibrations or sudden power loss.